If you look at battery use stats (under About Edge in Settings) you'll see that the LCD takes the vast majority of the power, followed by WiFi. Everything else together takes a miniscule proportion of battery power. This suggests to me that lowering LCD brightness (as well as setting a short LCD time-out time) can have a dramatic effect on battery life. Those who have the LCD at max brightness may deplete the battery especially fast.

I recommend adding Power Widget to your eDGe home screen. This way, you can easily toggle screen brightness, among other items.

Power Widget controls (from left to right):

(1) Wi-FI,
(2) BLUETOOTH (turns on, but not yet functional, so leave off for now),
(3) GPS (obviously does not apply to the eDGe),
(4) Background Sync (I believe this notifies you of new emails, etc, may use up some resources, including wifi), and
(5) BRIGHTNESS toggle